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Publishing Venue

Siemens

Related People

Juergen Carstens: CONTACT

Abstract

In mobile communication systems the frequency of channel condition changes depends on the mobile station velocity. A fixed algorithm of channel estimation/channel quality measurements works with good performance only in a limited range of mobile station velocity, outside this optimal range the algorithms' performance degrades significantly. For optimizing systems like UMTS (Universal Mobile Telecommunications System), E-UTRA (Evolved UMTS Terrestrial Radio Access) etc. in whole range of velocity an algorithm of channel estimation/channel quality measurements adapting to the mobile station velocity is desirable.
Until now this problem is not solved sufficiently. In the 3GPP (3rd Generation Partnership Project) Study Item "Evolved UTRA and UTRAN" is proposed to use different pilot structures in sub-frames, depending on the known velocity. Taking this into account emerging communication systems like E-UTRA try to solve this problem by using a different pilot density depending on the velocity (e.g. in case of low and medium mobility: two pilot fields per sub-frame and in case of high mobility: three pilot fields per sub-frame). But this concept has following disadvantages:

Copyright

SIEMENS AG 2005

Country

Poland

Language

English (United States)

This text was extracted from a PDF file.

This is the abbreviated version, containing approximately
52% of the total text.

In mobile communication systems the frequency of channel condition changes depends on the mobile
station velocity. A fixed algorithm of channel estimation/channel quality measurements works with
good performance only in a limited range of mobile station velocity, outside this optimal range the
algorithms' performance degrades significantly. For optimizing systems like UMTS (Universal Mobile
Telecommunications System), E-UTRA (Evolved UMTS Terrestrial Radio Access) etc. in whole range
of velocity an algorithm of channel estimation/channel quality measurements adapting to the mobile
station velocity is desirable.

Until now this problem is not solved sufficiently. In the 3GPP (3rd Generation Partnership Project)
Study Item "Evolved UTRA and UTRAN" is proposed to use different pilot structures in sub-frames,
depending on the known velocity. Taking this into account emerging communication systems like E-
UTRA try to solve this problem by using a different pilot density depending on the velocity (e.g. in case
of low and medium mobility: two pilot fields per sub-frame and in case of high mobility: three pilot fields
per sub-frame). But this concept has following disadvantages:

- It could increase the complexity of the frame construction/reception.

- The base station and mobile station have to know about the type of received/transmitted sub-
frames which may increase delay and signaling overhead.

To solve the problem described above it is proposed to use fixed pilot structures. This structure has to
be sufficient to support the highest velocity expected in E-UTRA, e.g. three pilot fields per sub-frame.
On...